Study Says Cars Make Us Fat

As if there weren’t already enough evidence proving regular exercise is good for you, a new study suggests ditching the car and walking, riding a bike or using mass transit can help prevent obesity.

In what might seem like a "Duh!" moment, David Bassett of the University of Tennessee and John Pucher of Rutgers University found a strong link between "active transportation" and obesity rates in 17 industrialized nations.

"Countries with the highest levels of active transportation generally had the lowest obesity rates," Bassett and Pucher conclude in the study published in the Journal of Physical Activity and Health. "Walking and bicycling are far more common in European countries than in the United States, Australia and Canada. Active transportation is inversely related to obesity in these countries."

Nowhere is this more obvious than the United States, where 12 percent of the population walks, rides a bike or takes mass transit, and as many as one in three people are obese.

The two researchers present their findings in "Walking, Cycling, and Obesity Rates in Europe, North America, and Australia," which examined health and travel data from 17 countries. In America, 9 percent of people walk, 1 percent ride a bike and 2 percent take the bus or train to get around, the study found. Yet 25 to 33 percent of Americans are obese. Compare that to other countries in the study:

Latvia: 67 percent of the population uses active transportation and 14 percent are obese.

Overall, the study found, Europeans walk three times as far and cycle five times as far as Americans. Europeans walk an average of 237 miles each year and bike another 116, while their American counterparts walk 87 miles and bike 24. The extra exercise means Europeans burn 5 to 9 pounds more than Americans do.

Looking at it another way, the Swiss take an average of 9,700 steps each day, compared to 7,200 for the Japanese and 5,900 here in America.

It would be easy to chalk this up to American laziness and our love affair with cars, but it isn’t that easy. European cities tend to be compact and densely populated with excellent transit systems. American cities, on the other hand, tend to sprawl on and on and on — ever been to Atlanta? Dallas? Phoenix? — and our mass transit infrastructure generally is not as advanced, so it can be harder to get out of the car and onto a bike.

It is important to note that several factors contribute to obesity, and the researchers do not conclusively prove that "active transportation" cuts obesity. But "they make an excellent case," Susan Handy, head of the Sustainable Transportation Center at the University of California at Davis tells the Associated Press.

"The question, then, is what do we do?" she says. "How do we get more people walking and biking in the U.S.?"